Protocols — PCI Bus Support
Version 1.10 12/01/02 12-5
Figure 12-4 shows an example of a larger server with one PCI Host Bus and four PCI Root Bridges.
The PCI devices attached to the PCI Root Bridges are all part of the same coherency domain. This
means they share a common PCI I/O Space, a common PCI Memory Space, and a common PCI
Prefetchable Memory Space. Each PCI Root Bridge produces one PCI Local Bus that can contain
PCI Devices on the motherboard or PCI slots. The firmware for this platform would produce four
instances of the PCI Root Bridge I/O Protocol.
OM13162
Core Chipset Components
PCI RB
PCI RB
PCI RB
PCI RB
PCI Host Bus
PCI Bus
PCI Bus
PCI Bus
PCI Bus
Figure 12-4. Server System with Four PCI Root Bridges